Blasting plug



Aug. 8, 1961 R. E. EDNEY ET AL BLASTING PLUG Filed sept. 4, 1959 UnitedStates Patent() BLASTING PLUG Robert E. Edney, Warrick County, andRaibourn McGee, Boonville, Ind.; said McGee assgnor to said Eduey FiledSept. 4, 1959, Ser. No. 838,142 2 Claims. (Cl. 102-30) The presentinvention `relates to a blasting plug, and more particularly to a newand novel blasting plug which is light in weight and virtuallyimpervious to water.

As is known, blasting plugs are commonly used in connection with theblasting operation in a mine or quarry. The blasting plug serves todirect the explosive forces into an area of maximum utility, and thus toprevent the surge of explosive force directly from the drill hole. Theprior devices for the above-mentioned purpose have been generallyobjectionable for several reasons including, and most principally, thefact that they were susceptible to water damage, either in storage orwhile in use; the materials -and/or weight thereof created manufacturingand/or shipping problems; and, the difficulty of positioning in thedrill hole, where the blocking of the latter was oftentimes ineffectiveas a result of the required tamping action.

By virtue of the instant invention, the applicants have provided a novelblasting plug for use in a drill hole in a mine or quarry which isvirtually impervious to water, which is light in Weight and, hence,readily transportable; and, which may be effectively positioned andreadily broken apart for use prior to the blasting operation. The`applicants novel blasting plug presents a wide contact area for thetamping action required thereon prior to blasting, i.e. when theblasting plug is positioned in the drill hole adjacent the explosivematerial.

In carrying out the principles of the instant invention,

the applicants employ a novel mixture of materials for forming theblasting plug including in various combinations and percentages, byvolume, cement; perlite, kenlite, or other lightweight aggregate;mortar; and, water. The aforementioned materials are molded to producethe novel instant blasting plug which comprises a generally rightcylindrical shell having a tapered or conical opening therethrough and acorrespondingly shaped conical plug adapted to be received in theconical opening in the shell. The shell has a plurality of slitsdisposed on the surface of the conical opening to permit the readybreaking thereof during the positioning of the blasting plug in thedrill hole.

Accordingly, the principal object of the present invention is to provideLa new and novel blasting plug which is virtually impervious to waterand yet which is light in weight.

Another object of the present invention is to provide a novel blastingplug which may be easily positioned for use in a drill hole, and whichat the same time is capable of being readily broken during positioningto block or plug the drill hole.

A still further object of the present invention is to provide a novelblasting plug made yfrom various combinations of material to effect `alightweight finished product.

A still further and more general object of the present invention is toprovide a blasting plug which is readily transportable, and yet which isadapted to prolonged exposure to the elements.

Other objects and la better understanding of the invention will becomemore apparent from the following description, taken in conjunction withthe iaccompanying drawing, wherein-- FIG. l is a view partly in verticalsection and partly in side elevation, taken at line 1-1 of FIG. 2 andlook- Patented Aug. 8, 1961 ing in the direction of the armws, showingdetails of the instant invention;

FIG. 2 is ya view in end elevation of the applicants novel blasting plugof FIG. l, taken at line 2 2 thereof and looking in the direction of thearrows, with the conical plug removed;

FIG. 3 is another end view of the blasting plug of FIG. l, taken at theopposite end thereof from the view of FIG. 2, also with the conical plugremoved; and,

FIG. 4 is a generally diagrammatic view showing the applicants novelblasting plug in use in la drill hole in a mine or quarry.

For the purposes of promoting lan understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawing and specific language will be used to describe the same. ItWill nevertheless be understood that no limitation of the scope of theinventions is thereby intended, such laltera.- tions and furthermodifications in the illustrated device, and such further applicationsof the principles of the inventions as illustra-ted therein beingcontemplated as would normally occur to one skilled in the art to whichthe inventions relate.

Referring now to the gures, the applicants novel blasting plug lilcomprises a generally right cylindrical shell 11 having a tapered orconica-lly shaped opening 11a extending therethrough. In the preferredembodiment of the invention, the conically shaped opening 11a has aplurality of slits 11b disposed on the surface thereof, for reasonswhich will be apparent from the discussion herebelow. A conical plug 14,which is complementary in shape to the conical opening 11a in the shell11 completes the blasting plug 10 assembly. It should be noted from FIG.l that in a position of nonuse, the conical plug 14 extends only partlyinto the conical opening 11a in the shell 11, `again for reasons whichwill be discussed more fully herebelow.

The blasting plug 10 forming the instant invention is made from a novelcombination of materials which provide, as a highly desired result, anend product which iS virtually impervious to water and which at the sametime is light in weight, features not present in the blasting plugsheretofore in use. The applicants make their novel blasting plug 10 frommaterial including, in various combinations, mixtures of cement; mortar;perlite, kenlite, or other lightweight aggregate; and, water,proportioned by volume.. For example, a typical mixture may includeapproximately two parts of cement, yfour parts of perlite and one partof water, which mixture is received in forms which shape the finishedproduct. Other effective combinations of material include cement,kenlite, and water; mortar, kenlite, and water; and, mortar, perlite,and water, all in a particular quantity relationship to achieve a stableyet readily breakable end product.

Referring now particularly to FIG. 4, a typical use of the novelblasting plug 10 is shown in connection with a drill hole 15 typicallyfound in a mine or quarry. After drilling the drill hole 15 to thedesired depth, and, of course, in the desired direction, a series ofexplosive charges 16 are disposed therein, which explosive charges 16are, for example, dynamite. The blasting plug 10 is then `disposed i-nthe drill hole 15 in the generally assembled relationship shown by FIG.4, so that the conical plug 14 thereof engages and abuts one of theexplosive charges 16. Tamping action then takes place by use of atamping member (not shown) which is generally of such diameter as toalmost completely ll the drilling hole 15 at one end thereof and fullyengage the end surface of the blasting plug 10.

As the tamping member is pushed against the blasting plug 10, in a leftto right `direction as shown in FIG. 4, the shell 11 rides upon theconical plug 14, whereupon Y3 the shell 11 readily breaks or fracturesdue to the longitudinal slits 11b therein. When the blasting plug 10 isbroken apart as described hereabove, it completely fills the drill hole15, and thereby effectively plugs or serves as a barrier between theexplosive charges 16 andthe outside mine shaft or other working area.

It should be particularly noted that the instant blasting plug isparticularly effective in that as the conical plug 14 and the conicallyshaped opening 11a in fthe shell 11 are each complementary in outwardconguration, a highly eective bearing area is provided which urges thebreaking of the shell 11 in a generally equal force relationship, Thelatter is in contrast to the former type blasting plugs where, in loneinstance, a conical plug e11- gaged a right cylindrical opening in acylindrical shell, such structure permitting only a line type of forceengagement.

It should be particularly emphasized that as the blasting plug 10forming the instant invention is made from one of the novel mixtures ofmaterials indicated hereabove, the finished product is light in weightyand virtually impervious to water. The latter feature is particularlyimportant in that oftentimes it is desired to leave the blasting vplugin the mine where it is damp, or perhaps in an area near the mineexposed to weather. Moreover, it should be readily apparent thattransporting the Vinstant blasting plug is simpliiied because of thewater impervious feature thereof which, together with the lightweightlfeature, combine to present a highly desirable type of product readilyadaptable -for long distance shipment.

Thus, it should be understood from the above that the applicants haveprovided `a new and improved blasting plug 10 made from a novelcombination of materials which is light in weight and yetwhich isimperious to water. The blasting plug promotes ready positioning in viewof the particular configuration of the components thereof, and yethighly eifective fracturing in the drill hole When'used In addition, andas fully disclosed hereabove,

the blasting plug is readily transportable and available for use asdesired, irrespective of its duration or place of storage.

The instant blasting plug is susceptible to various changes within thespirit of the invention. For example, more or less than the threelongitudinal slits may be disposed on the surface of the conical openingin the shell of the blasting plug depending, for example, upon theoverall `size of the plug with reference to the drill hole.

l Thus, the above description should be considered illustrative and notas limiting the scope of the following claims.

We claim: 1. A blasting plug assembly for a bore hole comprising, incombination, a one-pieceshell member having a l:tapered opening therein,and a plug member complementary in shape to said tapered opening in saidone-piece shell member and disposed in direct contact therewith, saidone-piece shell member having rupturable weakened sections and said plugmember also being rupturable, where said weakened sections of saidone-piece shell member and said plug member rupture to dene a unitaryblocking mass when placed in said bore hole prior to blasting, and Wheresaid one-piece shell member and said plug member are each made frommaterial consisting of approximately two parts of cement, four parts ofllightweight aggregate and one part of water.

2. A blasting plug assembly for a bore hole comprising, in combination,a one-piece shell member having a tapered'opening therein, and a plugmember complementary in shape to said tapered opening in said one-pieceshell member and disposed in direct contact therewith, said one-pieceshell member having rupturable weakened sections and said plug memberalso being rupturable, Where said weakened sections of said one-pieceshell member Vand said plug member rupture to define a unitary blockingmass when placed in said bore hole prior to blasting, and where saidone-piece shell member and said plug member are each made from materialconsisting of approximately two parts of mortar, four parts of light-Weight aggregate and one part of Water.

References Cited in the tile of this patent UNITED STATES PATENTS282,061 Dennett July 31, 1883 806,495 Rasmussen Dec. 5, 1905 1,078,442Johnson Nov. 11, 1913 2,040,581 Voortmann May 12, 1936 2,055,618 BlauSept. 29, 1936 2,388,232 Tappan Oct. 30, 1945 2,876,700 Householder Mar.10, 1959 FOREIGN PATENTS 175,749 Great Britain Feb. 20, 1922 351,998Great Britain July 2, 1931

